Copper-CatalyzedCarbocyclization of Silyl Enol Ether Tethered Ynamides for Efficient and Practical Synthesis of2-Azabicyclo[3.2.0] Compounds(dagger)

Summary of main observation and conclusion An efficient copper-catalyzed carbocyclization of silyl enol ether tethered ynamides has been developed, allowing rapid and practical construction of diverse 2-azabicyclo[3.2.0] compounds in generally good to excellent yields with broad substrate scope under mild reaction conditions. Importantly, this protocol not only constitutes a rare example of non-noble metal-catalyzed alkyne carbocyclization, but also represents a rare cyclization on the beta-position of pi-tethered ynamides. The possibility of asymmetric carbocyclization via kinetic resolution also emerges.